LONDON – A well-known privacy advocate has given the public an unusually explicit peek into the intelligence world's tool box, pulling back the curtain on the National Security Agency's arsenal of high-tech spy gear.

Appelbaum, a security expert and independent journalist, on Monday spoke to a hacker conference in Germany about dozens of purported NSA documents, including descriptions of how iPhones could be rigged to turn them into eavesdropping tools and radar wave devices that could harvest keystrokes even when a computer isn't connected to the Internet.

The provenance of the documents, which were first published by German magazine Der Spiegel, wasn't made explicit.

Appelbaum and Der Spiegel have both played a role in the disclosures of NSA leaker Edward Snowden, but neither has clarified whether these documents came from Snowden.